Dometic Circuit Board Temperature Adjust

[wdk450]

Gang:
I have been going round and round in the hot California Central valley heat with my Dometic NDR1292 double door refrig not quite keeping cold enough. I just finished a double fan upgrade today (so now the venting unit has 4 fans - I will discuss the fan upgrade in another ongoing thread), and STILL wasn't satisfied with the results. It crossed my mind that maybe the temperature sensing thermistor inside the refrig section was out of calibration. I found a 3rd party thermistor kit with an inline adjustment potentiometer. Shortly after I ordered this $27 part online, I read something somewhere about a thermistor temperature adjustment potentiometer on the refrigerator circuit board. I looked up the Dinosaur Electronics Dometic circuit board, and it had a notation about the temperature adjustment potentiometer. It is blue, square, located at the top left of the circuit board. The boards are shipped with the pot in the mid position, and you can even see "warmer" and "colder" silkscreened on the circuit board next to the pot (clockwise is colder).

I ran outside in the dark with my headlamp on and adjusted the pot to about the 3 o'clock position from the 12 o'clock position. I came inside and could see the temp going down by 0.1 degrees every 5 minutes or so. I will post final results on edit later, but thought that all the Dometic owners out there ought to know about this secondary temperature control.

 

[jhardin]

Thanks wdk450, keep us updated! I'm sure this will help a lot of us with the same problem.

Sent from my SM-G900V using Tapatalk

 

[danemayer]

Bill,

Since you were looking at documentation for a Dinosaur (replacement?) board, should we assume that's where the adjustment potentiometer was? If so, I'm not sure that would apply to the OEM board.

 

[wdk450]

Well, here is an update!!!

After running my fridge on propane (which seemed to get the refrig cooler), with the cooling demand cranked up on the circuit board for a week, and a few days after I completed my outside double cooling fans in the vent covers upgrade, the refrig started getting down near freezing inside one night. The outside high temperatures HAVE come down some, but are still maxxing out around 95 degrees, and forecast to go back up to the 100 degree range for a while. I am now even able to run it on AC heat satisfactorily. I went outside and adjusted the circuit board temp adjust back 45 degrees from the 90 degrees clockwise adjust I first gave it. Right now middle cold inside setting gives me about 2 degrees centigrade (35 F) in the refrig, and -12 C (-10F) in the freezer. I couldn't come close to these low temps before. I can now see ice forming in the condensate on the refrigerator condenser fins. Nothing seemed to IMMEDIATELY (2 days) happen after any of my attempts to make it better.

I am even speculating that with a lesser Northern arc of the sun, my refrig slide on the North side of the rig is now getting less direct sunlight.

I think that the fans in the vent covers is a good thing for this big refrig that does not have the top vent cover opening high enough up to effectively remove the hot venting air. I have another thread going on the fans upgrade, and I will take some pictures and make a post there today.

All in all, I can just say that my refrig/freezer is now getting cold enough, but I can't definitively say what fixed it.

 

[Gary521]

Probably a typo but -12 C is +10 F

 

[yukonjackman]

Thank you for the information I was wondering the settings, I installed it and my ice cream wasn't as cold